Concrete gun



W. F WEBB.

CONCRETE GUN.

APPLICATION FILED DEC- H, I919.

1,362,767. Patented Dec. 21, 1920.

2 SHEETSSHEET 1.

,INVENTOR WADE F. WEBB:

2 SHEETS-SHEET 2- TORNEY was I WADE F. WEBB:

W. F. WEBB.

CONCRETE GUN.

APPLICATION FILED 050.11. 19194 Patented Dec. '21, 1920.

UNITED STATES PATENT OFFICE.

WADE F. WEBB, OF KERNVILLE, CALIFORNIA.

CONCRETE-GUN.

To all whom it may cone-em:

Be it known that I, l/VADE F. WEBB, citizen of the United States,residing at Kernville, in the county of Kern and State of California,have invented new and useful Improvements in Concrete-Guns, of which thefollowing is a specification.

This invention relates to a concrete gun and particularly pertains to anair operated mechanism for conveying concrete through a conduit.

It is the object of this invention to provide effective means wherebyconcrete may be forced through a conduit by the direct action of airthereon, and embodying a mechanism for feeding a charge of concrete tothe conduit while it is being subjected to the conveying action of airunder pressure.

Another object is to provide a concrete gun embodying a receivingchamber having a piston therein adapted to advance the concretedelivered to the chamber toward a discharge nozzle, and also to providea means for reciprocating said piston by air under pressure.

Another object is to provide a novel piston construction which willpermit of the ready adjustment or removal and replacement of packingelements on the piston to compensate for the unusual wear to whichpacking rings in pistons employed for this purpose would be subjected.

Another object is to provide a construction and arrangement of parts ina concrete gun whereby it may be readily assembled and dismantled.

A further object is to provide means for removing concrete from theinner walls of the receiving chamber so as to reduce wear of the pistonandchamber walls.

Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is a View of the concrete gun in vertical section, partly inelevation;

Fig. is a transverse section as seen on the line 2-2 of Fig. 1, withparts broken away;

Fig. 3 is an enlarged vertical section on the line 3-3 of Fig. 2,showing the construction of the concrete advancing piston andillustrating the construction of the piston rings; 7

Fig. 1 is an enlarged detail sectionillustrating the construction of theair plston;

More specifically, 5 indicates a concrete Specification of LettersPatent. Patented D 21 1920 Application filed December 11, 1919.

Serial No. 344,134.

receiving chamber which is formed of a cylinder 6 preferably comprisingan ordinary iron pipe of suitable dimensions, preferably about 2 feet indiameter. This cylinder is formed with an inlet opening 7 in the upperportion and adjacent to one end thereof, fitted with a feed hopper 8,and the cylinder is also fitted with end flanges 9 and 10 here shown asscrewed thereon. The

end of the cylinder remote from the opening 7 connects with an eccentricreducer 11, the bottom wall of which is continued flush with that of thechamber 5 and the side and top walls of which taper to an outlet 12connecting with a conduit 13 leading to any suitable point of discharge.

Thereducer 11 is preferably detachably connected to the cylinder bymeans of bolts 14. or other suitable fastenings engaging the flange 10.

The end of the cylinder adjacent to the opening 7 is connected to acylinder 15, which is fitted with an end flange 16, and interposedbetween the cylinders 6 and 15 is a .plate 17 forming a partitionbetween the interiors of the cylinders, and which plate is here shown assecured between the flanges 9 and 16 by bolts 18 by which the cylindersare connected together. Thepartition plate 17 is formed with a centralopening through which a tubular piston stem 19 extends; packing rings 20encircling the margin of the opening in the partition plate to form apractically air tight olnt.

The piston stem 19 is preferably formed of pipe externally threadedatits ends to receive flange rings 21 and 22; the flange ring 21carrying a piston 23 positioned in the cylinder 6, and the flange ring22 carrying a piston 24 disposed in the cylinder 15. An importantfeature of the present invention resides in the construction of theforward and are here shown as comprising wooden segments 29 arranged inlayers of any suit able number and disposed with the joints between. thesegments of adjacent layers staggered or offset relative to each otherto form broken oints.

The front plate, carrying the packing member, is deniountably attachedto the back plate 26 by means of bolts 30, which are here shown aspassing through the front plate 27 and through the packing member andscrewed into engagement with the back plate 26, which constructionpermits of the front plate and packing members being removed from thepiston and replaced through the opening 7 so as not to necessitatedisconnection of the cylinders 6 and 15 when it is necessary to renewthe packing member on the piston.

The outer face of the front plate 27 is formed with a series of channels31 terminating in an inclined wall 32 at the outer edge of the plate andcommunicating at their inner ends with openings 33 leading to the innerside of the plate in communication with the space interiorly of theflange 28 which opens through the plate 26 to the tubular piston stem19, which is here shown as formed with an air inlet opening 34; adjacentto the piston 24 so as to admit air from the chamber within the cylinder15 and effect a discharge of a series of air jets from the forward endof the piston 23 adj acent its periphery and against the walls of thechamber 5.

The channels 31 are covered by a face plate 35, which is placed over thefront plate 27 and secured thereto by any suitable fastenings; the faceplate 35 affording a removable wearing surface and serving as aprotection to the front plate 27.

The pistons 23 and 24 are designed to be reciprocated by air underpressure, which is delivered alternately to the opposite sides of thepiston 2a through air inlet pipes 36 and 37 communicating throughcontrol valves 38 and 39, with a conduit 10 leading from any suitablesource of air under pressure.

The valve 38 is here shown as consisting of an ordinary three-way valveadapted to be positioned to either admit air under pressure to theouterend of the piston or to eX- haust the air therefrom. The valve 39 ishere shown as comprising an ordinary straight way cut-off valve foradmitting air under pressure to the inner side of the piston 24.

The air for conveying concrete through the conduit 13 is admitted to thechamber 5 through a conduit 4.1 leading into the upper portion of thereducer 11 through a regulating cut-01f valve 12.

The outer end of the cylinder 15 is closed by an end cap 13,which isscrewed thereon and with which the pipe 37 connects, and the piston 24is formed with packing rings 14 held in place by an end plate 45 adaptedto be removed and replaced through the open outer end of the cylinder 15when the end cap 43 is removed; the end plate 45 being secured by bolts46 to a back plate 47 carried on the end flange 22 of the piston stem.

In the operation of the invention, the piston 23 is retracted byadmitting air into the chamber within the cylinder 15 through the valve39, the air being admitted in such volume and pressure as to act on thepiston 24 to move the connected pistons rearwardly and at the same timesupply sufficient air to maintain a flow of air through the piston 23during the retraction thereof and clean the walls of the chamber 5. Thevalve 38 is opened to permit rearward movement of the pistons.

"When the piston 23 is in its retracted position, a charge of concreteis delivered to the chamber 5 through the hopper 8 and opening 7,whereupon the valve 39 is closed and the valve 38 opened to direct airunder pressure rearward of the piston 24:, so as to impel the latter ina forward direction, together with the piston 23.

The air in the chamber within the cylinder 15 will be discharged throughthe openings 34 and through the piston 23 against the walls of thechamber 5, as the pistons advance. The charge of concrete delivered tothe chamber 5 is shoved forward by the piston 23 toward the conduit 13,and when the piston 23 has reached a point beyond the opening 7, thevalve 42 is opened to admit air into the space within the chamber 5between the outer end of the piston 23 and the reducer, which air underpressure will operate to advance the concrete through the conduit and toconvey it to any suitable point of discharge remote from the receivingchamber.

The piston 23 is advanced such distance as to position the maj orportion of the charge into the reducer, whereupon the valve 38 is closedto the air supply and opened to exhaust and the valve 39 opened to theair supply to retract the pistons. The valve 42 may be left open untilthe piston 23 reaches the opening 7, whereupon it will be closed duringthe time the succeeding charge is delivered to the receiving chamber andthe piston 23 again advanced.

The abrasive character of the material being handled causes rapid wearof the packing member of the forward piston and necessitating occasionaladjustment or replacement of the packing members. By the construction ofthe piston as before described, this may be readily effected by removingthe front plate 27 through the intake opening 7.

lVhile I have shown and described a specific embodiment of my invention,it is manifest that various changes may be made in the details ofconstruction thereof, without departing from the spirit and scope of theinvention as set forth in the appended claims.

As a means for preventing backward movement of the pistons in event theconduit should become choked, the piston 24 is formed of an areaexceeding that of the piston 23 so that the pressure exerted by the airon the piston 24 would be greater than that exerted by back pressure onthe piston 23, thereby overcoming such back pressure. Any other suitablemeans may be employed for preventing accidental retraction of thepistons.

I claim:

1. In a concrete gun, a concrete receiving chamber, a discharge conduitconnected thereto, means for admitting air under pressure to saidchamber to convey concrete through said conduit, a piston in saidchamber for advancing a charge of concrete into position to be operatedon by air under pressure, and means for directing jets of air fromadjacent the periphery of said piston against the walls of the receivingchamher.

2. A concrete gun comprising a pair of cylinders, a partition plateinterposed between said cylinders, a piston in each of said cylinders, apiston stem connecting said pistons through said partition plate, meansfor directing air under pressure to the 0pposite sides of the piston inone of said cylinders for advancing and retracting said pistons, anintake opening being provided in the other cylinder through which acharge of concrete may be admitted to the latter forward of the pistontherein, a discharge conduit connected to said last named cylinder, andmeans for directing air under pressure in front of the piston in saidlast named cylinder to convey the charge of concrete through saidconduit.

3. A concrete gun comprising a pair of cylinders, a partition plateinterposed between said cylinders, a piston in each of said cylinders, apiston stem connecting said pistons through said partition plate, meansfor directing air under pressure to the opposite sides of the piston inone of said cylinders for advancing and retracting said pistons, anintake opening being provided in the other cylinder through which acharge of concrete may be admitted to the latter forward of the pistontherein, a discharge conduit connected to said last named cylinder,means for directing air under pres sure in front of the piston in saidlast named cylinder to convey the charge of concrete through saidconduit, and means for directing air through the piston in the lastnamed cylinder to direct air jets against the walls of the cylinder.

WADE F. WEBB.

